In accordance with reduction in the thickness and size of electronic devices and electronic components used in electronic devices, printed wiring boards to be connected to them via connectors are also required to have a reduced thickness and size. Reduction in the thickness and size of printed wiring boards, however, leads to deterioration in the engaging force between printed wiring boards and connectors. Therefore, if strong external force is applied to a printed wiring board connected to a connector, the printed wiring board may possibly be disconnected from the connector.
In view of preventing such disconnection of a printed wiring board from an electric connector for planar circuit boards, it is known to provide the printed wiring board with notches at locations opposite to each other at a pair of parallelly extending sides and fit engagement parts provided on the connector into the notches.